EVALUATING RADIATION CHANGE IN NUCLEIC ACIDS

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。这个项目的重点是电离辐射对DNA结构和能量学的影响。报道了鸟嘌呤-胞嘧啶碱基对电离的从头算研究结果。通过双质子转移产生的正则GC碱基对和稀有GC碱基对都受到电子的影响，并观察到几何和能量的变化。这些碱基对允许利用五个基组(6-31G(D)、6-311G(D)、6-311G(d，p)、aug-cc-pVDZ和DZP++)在B3LYP理论水平上进行优化。当电子连接时，两种物种都表现出相当大的非平面性。此外，电子亲和能和相对能量表明，在这些条件下，稀有形式可能是有利的。这可能暗示了DNA在加电子时利用的一种新机制。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The focus of this project is the effect of ionizing radiation on DNA structure and energetics. The results of an ab initio study of ionization of guanine-cytosine base pair are reported. Both the canonical GC base pair and the rare GC base pair, created by a double proton transfer are subject to the inclusion of an electron and the geometric and energetic changes were observed. These base pairs were allowed to optimized at the B3LYP level of theory utilizing five basis sets (6-31G(d), 6-311G(d), 6-311G(d,p), aug-cc-pVDZ, and DZP++). Both species showed considerable nonplanarity when the electron is attached. Futhermore, the electron affinities and relative energies show that the rare form may be favored under these conditions. This may suggest a new mechanism that DNA utilizes upon addition of an electron.